This invention relates to a liquid jetting apparatus having a head member capable of jetting drops of liquid from nozzles. In particular, this invention relates to a liquid jetting apparatus that can suitably control a full-jetting state, which is called xe2x80x9cfully-coveringxe2x80x9d.
In a ink-jetting recording apparatus such as an ink-jetting printer or an ink-jetting plotter (a kind of liquid jetting apparatus), a recording head (head member) can move in a main scanning direction, and a recording paper (a kind of recording medium) can move in a sub-scanning direction perpendicular to the main scanning direction. While the recording head moves in the main scanning direction, a drop of ink can be jetted from a nozzle of the recording head onto the recording paper. Thus, an image including a character or the like can be recorded on the recording paper. For example, the drop of ink can be jetted by causing a pressure chamber communicating with the nozzle to expand and/or contract.
The pressure chamber may be caused to expand and/or contract, for example by utilizing deformation of a piezoelectric vibrating member. In such a recording head, the piezoelectric vibrating member can be deformed based on a supplied driving-pulse in order to change a volume of the pressure chamber. When the volume of the pressure chamber is changed, a pressure of the ink in the pressure chamber may be changed. Then, the drop of ink is jetted from the nozzle.
In such a recording apparatus, a driving signal consisting of a series of a plurality of driving-pulses is generated. On the other hand, printing data including level data (gradation data) can be transmitted to the recording head. Then, based on the transmitted printing data, only necessary one or more driving-pulses are selected from the driving signal and supplied to the piezoelectric vibrating member. Thus, a volume of the ink jetted from the nozzle may be changed based on the level data.
The above recording apparatus can be used for jetting a plurality of kinds of ink. In the case, it is preferable that a driving signal is generated for each of the plurality of kinds of ink. However, in order to avoid problems such as cost in forming a circuit for generating the respective driving signals, a common driving signal may be used for all the plurality of kinds of ink.
In the latter case, it is usual that a controlling state for xe2x80x9cfully-covering (fully-painting)xe2x80x9d wherein level data of the highest density are continuous is adjusted for a kind of ink difficult to achieve the xe2x80x9cfully-coveringxe2x80x9d, that is, a kind of ink having a low ink-expansion characteristic (for example, a black ink).
However, if the xe2x80x9cfully-coveringxe2x80x9d control is adjusted for the kind of ink having a low ink-expansion characteristic, regarding a kind of ink having a high ink-expansion characteristic (for example, a color ink), an amount of ink more than necessary to achieve the xe2x80x9cfully-coveringxe2x80x9d is jetted, which tends to generate some oozy ink, which may cause a deterioration of recording quality.
In order to avoid the above problem, the inventor studied to adopt a xe2x80x9cDUTY limitxe2x80x9d. However, if the xe2x80x9cDUTY limitxe2x80x9d is adopted, the resolution and the level steps are also reduced, that is, it becomes difficult to maintain the high recording quality.
In addition, in the above recording head, in order to improve the recording speed or the like, a plurality of nozzles may be formed in the recording head. In the case, the characteristic of jetting an ink drop in each nozzle may be different from each other, because of a reason regarding manufacture of the recording head or the like.
In conventional recording heads, there is no attempt to precisely adjust the volume (weight) of an ink drop jetted from each nozzle for one pixel according to the same level datum. However, if the volume (weight) of an ink drop jetted from a nozzle for one pixel according to the same level datum is different from that from another nozzle, a problem about the recording quality may be generated in particular in a full-jetting (fully-covering) control.
The inventor studied to generate a driving signal for each nozzle in order to jet a proper volume (weight) of ink drop always. However, in the view of cost in forming a circuit for generating the driving signals or the like, the inventor judged that the concept is not practical at least for the present.
The object of this invention is to provide a liquid jetting apparatus such as a ink-jet recording apparatus that can suitably control a full-jetting state called xe2x80x9cfully-coveringxe2x80x9d, even if a common driving signal is used for respective kinds of liquid.
In order to achieve the object, the invention is a liquid jetting apparatus comprising: a head member having a nozzle; a pressure-changing unit that can cause pressure of liquid in the nozzle to change in such a manner that the liquid is jetted from the nozzle; a jetting-mode setting unit that can set a selected jetting mode from a plurality of jetting modes; a driving-signal generator that can generate a common jetting-driving signal; a driving-pulse generator that can generate a full-jetting driving pulse, based on the selected jetting mode and the common jetting-driving signal; and a full-jetting main controller that can cause the pressure-changing unit to operate, based on the full-jetting driving pulse.
According to the above feature, since the full-jetting driving pulse is generated based on the selected jetting mode and the common jetting-driving signal, even if the common jetting-driving signal is used for a plurality of kinds of liquid, the full-jetting state can be controlled suitably for each of the plurality of kinds of liquid.
Preferably, weights of the liquid jetted from the nozzle based on respective full-jetting driving pulses are different according to respective jetting modes. That is, by making actual weights of the jetted liquid different, a uniform xe2x80x9cfully-coveringxe2x80x9d can be easily achieved even although the respective kinds of liquid have respective liquid-expansion characteristics.
Preferably, the common jetting-driving signal is a periodical signal including a plurality of (separated) the same pulse-waves within a period thereof, and the driving-pulse generator is adapted to generate a rectangular-pulse row corresponding to the period of the common jetting-driving signal based on the selected jetting mode, and generate an AND signal of the rectangular-pulse row and the common jetting-driving signal as the full-jetting driving pulse.
If the above manner is adopted, a process of generating the full-jetting driving pulse can be easily materialized.
In a concrete example, if the plurality of jetting modes include a first jetting mode and a second jetting mode, and the common jetting-driving signal is a periodical signal including n the same pulse-waves within a period thereof, the driving-pulse generator can generate a full-jetting driving-pulse including only p pulse-waves when the selected jetting mode is the first jetting mode, p being one or more, and another full-jetting driving-pulse including only q pulse-waves when the selected jetting mode is the second jetting mode, q being more than p and not more than n, based on the common jetting-driving signal.
In the case, for example, a weight of the liquid jetted from the nozzle based on the one pulse-wave is 7 ng.
In addition, for example, n=7, p=5 or 6, and q=7.
In addition, preferably, the jetting-mode setting unit has: an input part into which desired dense-thin information is inputted by a user, and a jetting-mode setting main part that is adapted to set a selected jetting mode based on the desired dense-thin information inputted into the input part. In the case, a xe2x80x9cfully-coveringxe2x80x9d control based on dense-thin desire of the user can be achieved.
In detail, for example, the jetting-mode setting main part can change at least one of p and q, based on the desired dense-thin information inputted into the input part.
In addition, it is preferable that the jetting-mode setting unit sets as a selected jetting mode the first jetting mode when the liquid has a high liquid-expansion characteristic, and the second jetting mode when the liquid has a low liquid-expansion characteristic.
The reason is that when the liquid has a high liquid-expansion characteristic, a sufficient xe2x80x9cfully-coveringxe2x80x9d control can be achieved by a smaller amount of the jetted liquid, while when the liquid has a low liquid-expansion characteristic, a sufficient xe2x80x9cfully-coveringxe2x80x9d control needs a larger amount of the jetted liquid.
In addition, preferably, the jetting-mode setting unit has: an information reader that can obtain liquid information regarding the liquid included in a liquid cartridge from the liquid cartridge, the liquid cartridge being mounted on the head member; and a jetting-mode setting main part that is adapted to set a selected jetting mode based on the liquid information obtained by the information reader.
In the case, since the liquid information regarding the liquid included in the liquid cartridge can be obtained by the information reader, a xe2x80x9cfully-coveringxe2x80x9d control can be achieved suitably for each of the plurality of kinds of liquid.
In addition, preferably, the jetting-mode setting unit sets as a selected jetting mode the first jetting mode when a medium onto which the liquid is jetted has a high liquid-expansion characteristic, and the second jetting mode when the medium onto which the liquid is jetted has a low liquid-expansion characteristic.
In addition, the invention is a controlling unit that can control a liquid jetting apparatus including a head member having a nozzle, and a pressure-changing unit that can cause pressure of liquid in the nozzle to change in such a manner that the liquid is jetted from the nozzle; the controlling unit comprising: a jetting-mode setting unit that can set a selected jetting mode from a plurality of jetting modes; a driving-signal generator that can generate a common jetting-driving signal; a driving-pulse generator that can generate a full-jetting driving pulse, based on the selected jetting mode and the common jetting-driving signal; and a full-jetting main controller that can cause the pressure-changing unit to operate, based on the full-jetting driving pulse.
In addition, the object of this invention is to provide a liquid jetting apparatus such as a ink-jet recording apparatus that can suitably control a full-jetting state called xe2x80x9cfully-coveringxe2x80x9d, even if a characteristic of jetting a liquid drop in a nozzle is different from that in another nozzle, because of a reason regarding manufacture of a head member or the like.
In order to achieve the object, the invention is a liquid jetting apparatus comprising: a head member having a plurality of nozzles; a plurality of pressure-changing units each of which can cause pressure of liquid in each of the plurality of nozzles to change in such a manner that the liquid is jetted from the nozzle; a driving-signal generator that can generate a common jetting-driving signal; a mode storing unit that can store a jetting-amount-adjusting mode that has been set for each of the plurality of nozzles; a driving-pulse generator that can generate a full-jetting driving pulse for each of the plurality of nozzles, based on the jetting-amount-adjusting mode and the common jetting-driving signal; and a full-jetting main controller that can cause each of the plurality of pressure-changing units to operate, based on the full-jetting driving pulse.
If the plurality of nozzles forms a plurality of nozzle rows, the characteristics of jetting a liquid drop in the nozzles forming the same nozzle row tend to be the same, because of a reason regarding manufacture of a head member or the like. Thus, in order to achieve a control for jetting a liquid drop more simply, it is preferable to adopt a control manner not for each nozzle but for each nozzle row.
That is, the invention is a liquid jetting apparatus comprising: a head member having a plurality of nozzles forming a plurality of nozzle rows; a plurality of pressure-changing units each of which can cause pressure of liquid in each of the plurality of nozzles to change in such a manner that the liquid is jetted from the nozzle; a driving-signal generator that can generate a common jetting-driving signal; a mode storing unit that can store a jetting-amount-adjusting mode that has been set for each of the plurality of nozzle rows; a driving-pulse generator that can generate a full-jetting driving pulse for each of the plurality of nozzle rows, based on the jetting-amount-adjusting mode and the common jetting-driving signal; and a full-jetting main controller that can cause each of the plurality of pressure-changing units to operate, based on the full-jetting driving pulse.
According to the above respective features, since the full-jetting driving pulse is generated based on the jetting-amount-adjusting mode and the common jetting-driving signal, the full-jetting state can be suitably controlled, even if a characteristic of jetting a liquid drop in a nozzle is different from that in another nozzle, or even if a characteristic of jetting a liquid drop in a nozzle row is different from that in another nozzle row.
Preferably, the common jetting-driving signal is a periodical signal including a plurality of the same pulse-waves within a period thereof, and the driving-pulse generator is adapted to generate a rectangular-pulse row corresponding to the period of the common jetting-driving signal based on the jetting-amount-adjusting mode, and generate an AND signal of the rectangular-pulse row and the common jetting-driving signal as the full-jetting driving pulse.
If the above manner is adopted, a process of generating the full-jetting driving pulse can be easily materialized.
In a concrete example, if the jetting-amount-adjusting mode may be a first adjusting mode for a nozzle from which a larger amount of the liquid tends to be jetted or a second adjusting mode for a nozzle from which a smaller amount of the liquid tends to be jetted, the common jetting-driving signal is a periodical signal including n the same pulse-waves within a period thereof, and the driving-pulse generator can generate a full-jetting driving-pulse including only p pulse-waves when the jetting-amount-adjusting mode is the first adjusting mode, p being one or more, and another full-jetting driving-pulse including only q pulse-waves when the jetting-amount-adjusting mode is the second adjusting mode, q being more than p and not more than n, based on the common jetting-driving signal.
Alternatively, if the jetting-amount-adjusting mode may be a first adjusting mode for a nozzle from which a larger amount of the liquid tends to be jetted or a second adjusting mode for a nozzle from which an intermediate amount of the liquid tends to be jetted or a third adjusting mode for a nozzle from which a smaller amount of the liquid tends to be jetted, the common jetting-driving signal is a periodical signal including n the same pulse-waves within a period thereof, and the driving-pulse generator can generate a full-jetting driving-pulse including only p pulse-waves when the jetting-amount-adjusting mode is the first adjusting mode, p being one or more, another full-jetting driving-pulse including only q pulse-waves when the jetting-amount-adjusting mode is the second adjusting mode, q being more than p, and another full-jetting driving-pulse including only r pulse-waves when the jetting-amount-adjusting mode is the third adjusting mode, r being more than q and not more than n, based on the common jetting-driving signal.
In the above cases, for example, a weight of the liquid jetted from the nozzle based on the one pulse-wave is 3 to 5 ng.
In addition, the invention is a controlling unit that can control a liquid jetting apparatus including a head member having a plurality of nozzles, and a plurality of pressure-changing units each of which can cause pressure of liquid in each of the plurality of nozzles to change in such a manner that the liquid is jetted from the nozzle; the controlling unit comprising: a driving-signal generator that can generate a common jetting-driving signal; a mode storing unit that can store a jetting-amount-adjusting mode that has been set for each of the plurality of nozzles; a driving-pulse generator that can generate a full-jetting driving pulse for each of the plurality of nozzles, based on the jetting-amount-adjusting mode and the common jetting-driving signal; and a full-jetting main controller that can cause each of the plurality of pressure-changing units to operate, based on the full-jetting driving pulse.
In addition, the invention is a controlling unit that can control a liquid jetting apparatus including a head member having a plurality of nozzles forming a plurality of nozzle rows, and a plurality of pressure-changing units each of which can cause pressure of liquid in each of the plurality of nozzles to change in such a manner that the liquid is jetted from the nozzle; the controlling unit comprising: a driving-signal generator that can generate a common jetting-driving signal; a mode storing unit that can store a jetting-amount-adjusting mode that has been set for each of the plurality of nozzle rows; a driving-pulse generator that can generate a full-jetting driving pulse for each of the plurality of nozzle rows, based on the jetting-amount-adjusting mode and the common jetting-driving signal; and a full-jetting main controller that can cause each of the plurality of pressure-changing units to operate, based on the full-jetting driving pulse.
For example, the pressure-changing unit may have a piezoelectric vibrating member.
For example, the liquid is a kind of ink.
A computer system can materialize the controlling unit or any element of the above controlling unit.
This invention includes a storage unit capable of being read by a computer, storing a program for materializing the controlling unit or the element in a computer system.
This invention also includes the program itself for materializing the controlling unit or the element in the computer system.
This invention includes a storage unit capable of being read by a computer, storing a program including a command for controlling a second program executed by a computer system including a computer, the program being executed by the computer system to control the second program to materialize the controlling unit or the element.
This invention also includes the program itself including the command for controlling the second program executed by the computer system including the computer, the program being executed by the computer system to control the second program to materialize the controlling unit.
The storage unit may be not only a substantial object such as a floppy disk or the like, but also a network for transmitting various signals.